Hello Dr.Peter
Thank you for helping out.
There are around 75 or so domains pointing to the main website. When they were parked (prior to November 2014) on the main site, they were added as additional domains, which were url masked. So at least 30 domains were indexed in google with same content as main content.
12 months back, I realized the duplicate content error and changed the domain parking to 301 redirects. Also used ‘remove url’ functionality in Google Webmaster tools. Even after 12 months, I noticed a number of domains had duplicate contents in google index.
This I removed the pages from the addon domains again using google webmaster tools.
To give you an idea my main site with original content/links is iscripts.com and an addon domain socialappster.com is pointed to a product page at iscripts.com/socialware. If you do a site: socialappster.com in google you find few pages in google index, even though it is 301 redirect for more than 12 months now. Similar issue with other domains pointing to product pages as well as whole site.
Appreciate any direction you can provide to clean this mess.
Thanks
Aji Abraham